-The High Frequency (HF) antenna system for a Type VII U-boat consisted of three "jumping-wire" (end-fed long wire) antennas that could be individually selected and tuned as needed by the radio operator.

-The "jumping-wire" antennas were made of galvanized steel wire.

-The boat had one bow "jumping-wire" antenna and two stern "jumping-wire" antennas.  The bow antenna was usually used for transmitting.  The two stern antennas were most commonly used for receiving.

Photo by Klaus Mattes

Photo by kind permission of the German Naval Association